Sizing device for honing apparatus



Jan. 21, 1958 s. M. CALVERT sxzmc. DEVICE FOR HONING APPARATUS 4 Sheets-Sheet 1 Filed Jul 11,1956

INVENTOR. 6/977 M 6474? 12 Jan; 21, 1958 G. M. CALVERT 2,820,328

SIZING DEVICE FOR HONING APPARATUS Filed July 11, 1956 4 sheets sheet 2 IN V EN TOR. 67677 )7 64/1 075 Jan. 21, 1958 G. M. CALVERT sxzmc DEVICE FOR HONING APPARATUS :Filed July 11, 1956 4 Sheets-Sheet 3 Jan. 21, 1958 G. M. CALVERT 2 SIZING DEVICE FOR HONING APPARATUS Filed July 11, 1956 '4 Sheets-Sheet 4 A Jf/ A INVENTOR. I

2,820,328 srznso nnvrcn FOR HoNlNG APPARATUS Glen M. Calvert, Detroit, Mich.

Application July 11, 1956, SerialNo. 597,179

13 Claims. ((31. 51-34 This inventionrelates to honing apparatus for honing the bores of workpieces wherein honing devices are op-i erated by a reciprocable shaft or spindle and annular plug gage means encircles, or embraces the shaft or spindle and acts during operation on the same end of the workpiece bore as thehoning devices enter. In accordance with the operation of such apparatus the gage means is axially movable relative to the shaft or spindle and is adapted to have predetermined operative entry or passage into the workpiece bore when the bore has been honed to a predetermined diameter, such entry or passage of the gage means into the bore resulting in the actuation by the gage means of a limit switch or control device which in turn initiates cessation or termination of the honing operation, the latter being accomplished by releasing the honing devices from honing engagement with the work-' A further object of the invention is to provide stepped.

sizing or. gage ring means for controlling the diameter to which the workpiece bore is to be honed, said means preferably comprising a plurality or series of juxtaposed gage rings such, for example, as four thereof. Each gage ring is provided with two pairs of equally and annularly spaced gage elements or portions projecting radially outwardly from the body of the gage ring, the outer effective diameter across each pair of opposed gage elements on each gage ring corresponding to the desired diameter of the finished bore of the workpiece as determined by the pre-selected gage ring. The effective diameters of the series of gage rings progressively increase in such dimensional increments as desired thereby enabling the workpiece bore to be honed to any one of the elfective diameters'of the series of gage rings whereupon cessation or termination of the honing operation is initiated.

A further object of the invention is to provide stepped diameter sizing or gage ring means, such as above indicated, together with adjustable means for rendering any step of the gage ring means effective at the moment the limit switch or control device is actuated. Suchadjustable means may take several difiererit forms. "In accordance with the first embodiment of the invention, herein illustrated, there is provided an adjustable limit switch adapted to be actuated at any one of successive positions of adjustment by switch actuating means movable axially in unison with the stepped gage ring means. In accordance with asecond embodiment of the invention, herein illustrated, the switch actuating means, which moves axially in unison with the stepped gage ring rneans, is adjustable relative to thelimit switch into any oneoi successive positions. In accordance with a third emtates bodiment of the invention, herein illustrated, the stepped gageri'ng means is adjustable axially into any one of 9 p siti n h cbyj ar i the moment. jf a r tuation of the limit switcher control device. Thus, iii accordance with the several embodiments, the actuation of the limit switch'is controlled so as; to'takeI effect when.

any selected step of the gage ring means operatively renters the 'bo re of the workpiece. Other'objects and features ofthis invention will appear in the following description and appended claims, ref;

erence being had to the. accompanying drawings formingv a part of this' specification wherein like referencecharaeters' designate corresponding parts in the 'severaliviews Fig. 1 is a view inelevat'ion andpartly in longitudinal mid-section illustrating a honing apparatus constructed in' 'accordance with one embodirnenttof the present;

vention.

Fig. 2 is an enlarged side elevation taken in the direction of the arrows from the line 22 of Fig, l

Fig 3 is an enlarged plan view, partly in section, taken from the line 3-3 of Fig. 1 looking in the directionof the arrows. i

Fig. 4 is an enlarged fragmentary sectional, view of,

the structure bounded by n urers: line4in Fig. 1".

Fig. 5 is an enlarged transverse sectional; view taken in the direction of the arrows:alongithe line 55 or F .3. 6 is a fragmentary ra sver' s ss t snaview aken 6--6 of 4 in the directionofthe through the" line arrows.

Fig.7 is an enlarged plan view of a second en hodiment of the invention illustrated in Fig.8.

Fig. 8 is a fragmentary front elevation of. the second embodiment of the present invention.

Fig. 9is a side elevation of the structure shownin Fig. 8 1

taken in the direction of the arrows from the line 9-9 in Fig. 8. i

side elevation illustrating Fig. 10 is a fragmentary a third embodiment of' the present invention.

Before explaining in detail thep'resenhinvention it is .to be understood that theinventiorifis notlirnited in m e purpose of deser pnonand at its upper or drivenend to'the conventional machine spindle. The honing tool, depending upon the type of machine with which it is used,- may extend either vertically, or at an angle such as 45 or horizontally. In the present instance the tool is shown in animal po- -sition, a'lthough it is understood that this is rner'ely for illustrative purposes.

In accordance with the present embodiments of the invention the honing tool isprovide'd at its lower end with an abrading head 12 which may be con's'truc tedand operated in substantially the same manner asfthe'abra d ing head in. my copending application Serial No.8901555. The abrading head is carried by a lower enlarged end of a tubular shaft or supporting member 13 which extends upwardly from the 'abrading head 12. The hon ing tool in the presentembodiments is provided with'a tubular honing tool spindle member 14 formed at'its lower end with a reduced cylindrical portion'14atele scopically received withinthe upper portion of th'e'tubu lar shaft or supporting member 13 and secured'the'reto against relative displacement by airadiallye xtending' pin 15. At its upper end the spindle member 14 is pro.

vided with external threads 16. A tubular pilot member 17 has a reduced lower portion fitting within the upper end of the spindle 14 and attached thereto through the medium of pin 18. Threaded onto the upper end of the spindle member 14 are lock nuts 19. Secured to the pilot member 17 are pins 20 for connecting the pilot member to a hollow spindle coupling which in turn is connected, in accordance with conventional practice, to suitable mechanism for reciprocating and rotatmg the spindle 14, shaft member 13 and the abrading or honing tool head 12.

Extending freely through the tubular spindle member 14 and shaft member 13 is a cone rod 21 connected at its lower end to cone means (not shown) for movmg the abrading elements 12a radially outwardly against the surface of the bore of the workpiece W within which the abrading head 12 is located, as shown in Fig. 1. In the present instance radial outward movement of the abrading elements 12a is accomplished by axial movement of the cone rod 21 in a downward direction. Upon completion of the honing operation the cone rod 21 is shifted in an upward direction thereby enabling the abrading elements 12a to be moved radially inwardly free of the work by means of springs (not shown). The foregoing construction is fully illustrated in my above identified application Serial No. 390,555.

The upper end 21a of the cone rod 21 is adapted to be contacted by an incremental feed means, such as illustrated in my above identified application. Such feed means progressively forces the cone rod 21 downwardly to cause the cone means at the lower end thereof to expand the abrading elements 12a against the bore of the workpiece W. Spring restoring means is provided for shift ng the cone rod 21 upwardly when the pressure of the incremental feed means is released, thus permitting the abrading elements 12a to move radially inwardly. Upward shiftable movement of the cone rod 21 is accomplished by means of a coil spring 22 having the lower end thereof engaging an annular shoulder 14b on the spindle member 14. The upper end of this spring engages a washer 23 embracing the cone rod 21 and held in position by pins 23a secured to the cone rod. Thus, it will be seen that upon release of downward pressure on the cone rod 21 by the incremental feed means the spring 22 will shift the cone rod 21 upwardly thus permitting the abrading elements to collapse.

In addition to the foregoing the honing tool in each of the embodiments is provided with a cylindrical gage rlng supporting body 24 terminating at its upper end in an outwardly extending annular flange 24d. Underlying the outer portion of this flange is a lock ring or holder 25 attached by means of screws 26 to a cylindrlcal gage control body 27. This body is provided with an inwardly extending annular flange 27a overlying the flange 24a of the gage support 24. The ring 25 and flange 27a are spaced apart to provide an annular channel receiving the gage support end flange 24a, such channel having an axial width slightly exceeding the axial thickness of the flange 24a thereby permitting the latter to shift laterally or transversely of the spindle 14 without appreciable frictional resistance within the channel. The internal diameter of the cylindrical gage support 24 is appreciably greater than the external diameter of the spindle 14 so as to permit the gagesupport 24 to shift or float laterally relative to the spindle a substantial amount, such as from ten to thirty thousandths of an inch, depending upon the type of work being honed. This lateral shifting or floating of the gage support 24 is also permitted by the depth of the annular space between the lock ring 25 and flange 27a which permits the flange 24a of the gage support to shift or float laterally an amount, such as from ten to thirty thousandths of an inch.

27 and the spindle member 14 is an upper ball race ring 28 which is unconnected and free with respect to the members 14 and 27. Underlying the ring 28 is a second ball race ring 29 which is also free from connection with the members 14 and 27. Interposed between ball race rings 28 and 29 are anti-friction ball bearings. A compression spring 30 is interposed between the ball race ring 29 and a bushing 31. This bushing is free with respect to the spindle member 14 and has the lower end thereof securely press fitted into the cylindrical gage control body 27 so as to have no rotative movement imparted thereto by the spindle member 14.

A limit switch control member or arm 32 fits within a vertical slot in the gage control body 27, being attached thereto by means of screws 33. A trip block 34 is attached to the upper end of the limit switch control member 32. This strip block is provided with a laterally extending arm 34a having a tapped hole for adjustably receiving a limit switch actuating screw 35 terminating in an annular head 35a forv engaging and actuating the limit switch. The adjusting screw 35 is held in adjusted position by means of a lock screw 36.

The cylindrical laterally floating gage support 24 is formed with external threads 24b and, as particularly shown in Figs. 4 and 5, is formed with four equally spaced vertical slots 37. A tubular gage holder 38 is provided with internal threads in threaded engagement with the threads 24b on the gage support 24. The gage holder 38 through its threaded connection with the gage support 24 is vertically adjustable thereon. The gage holder 38 is formed with an upper outwardly projecting annular flange 38a having a tapped hole to receive a set screw 39 and a lock screw 40, see Figs. 4 and 5. The gage holder, when adjusted axially on the gage support 24 through its threaded connection therewith, is positioned after adjustment so that the set screw 39 may project into any one of the four anchoring slots 37 thereby holding the gage holder and gage support against relative annular displacement.

, Mounted upon and embracing the tubular gage holder 38 and below the annular flange 38a thereof are a series of gage rings, four thereof being illustrated by way of example in the present embodiments of the invention.

From the lower to the upper thereof these gage rings are designated A, B, C and D and are positioned in snug surface engagement one with another. In preferred practice the gage rings are fabricated separately although they could be embodied integrally in a unit. The gage rings are held in contact relation, with the upper gage ring D in firm engagement with the flange 38a, by means of a gage holding ring 45 which projects into an annular notch or groove 46 in the lower gage ring A. The ring 45 is secured to the gage holder 38 by means of four holding screws 47 which may be firmly tightened so as to hold or clamp the gage rings together between the clamping ring 45 and the shoulder 38a on the gage holder 38.

As illustrated in Fig. 5, the gage ring D is formed with two pairs of oppositely disposed protuberances or projecting portions 44, each having a slot or notch to receive a hard wear insert 51. These wear inserts are preferably formed of carbide or other wear resisting alloy. The outer surfaces of the wear inserts 51 and the adjacent surfaces of the projections 44 are machined to provide arcuate gaging or sizing surfaces of effective diameter. The gage rings A, B and C are provided, respectively,

with two pairs of oppositely disposed protuberances or projections 41, 42 and 43 which are similar to the projections 44. The projections in each of the gage rings A, B and C are slotted or notched to receive hard wear inserts 48, 49 and 50, respectively. The construction of the four gage rings A, B, C and D with their hard wear inserts is the same and as illustrated in Figs. 5 and 6. However, it will be noted from Figs. 4 and 6 that the projections 44 of the gage ring D extend radially and outwardly slightly beyond the projections 43 of the a -fin C; n. ke manner,i eseproiep ionsrta extend.

ad a l nd qutwar yn i hny y n he. projections hu e-awe i g B1 operative. entry. of anyaoneof the gagerings A-D into.

the honedbore. The'four gage projections or. gage elements 41 together with their wear inserts 48 terminate V in ,.tapering lead portions orcam means 48a which progressively. narrowinefiective diameter, and are adapted to .disjplace or cam the gage rings. laterally due tothe lateral float mounting of gage support 24 thereby. center.- ingthe gage rings axially with thebore of the workpiece.

In the embodiment of Figs, 1 to 6 inclusive thefeed means, which may be hydraulic or' othersuitable mechanism, for shifting the cone rod or shaft 21, is controlled by an adjustable limit switch generally indicated at 2 ha ving a switch actuating member 53 adapted to be engaged by member 35a. The limit switch 52 is carried by a supporting member 54 having a projecting knob 54a. This supporting member is attached to a vertically adjustable slide 55 shiftably mounted on astationary guide bracket 56 having an angle flange 56a providing a guide abutment for one vertical edge of the slide. The guide bracket 56, see Fig. 2, is attached to a stationary bracket 57 by screws 57a, this bracket being attached to, and. carried by a stationary fixture bushing 58 (Fig. 1) secured to. a fixture frame 59. It will be understood that the central vertical opening through the bushing 58 permits free vertical passage therethrough of the honing tool.

Asshown particularly in Figs. 2 and 3, there is provided a spring retainer 60 having a recess 61' within which extends a compression spring 62 disposed between the bottom of the recess and a washer 62 slidably engaging the outer face of the bracket 56. The spring retainer 60 is adjustably held by the head of ashoulder screw 63 having itsithreaded shank extending through and slidable within a vertical slot 64 in guide bracket 56. The end oithe shank of screw 63 is threaded at 65 into a tapped hole in the slide 55. By virtue of this construction the slide 55 is yieldingly held in proper vertically adjusted position with respect to the guide, bracket 56.

The free vertical edge of the slide 55 is provided with a series of four vertically spaced latching notches 66, 67, 68 and 69. Adjacent the edge of the limit switch adjusting slide 55 is a selector lever pivoted at 70 to the bracket 56. This lever has a downwardly extending lever arm 71 provided with a projecting locking lug or detent 71a adapted to project into any one of the notches 66-69 so as to hold the slide 55 in vertically adjustedposition. Extending upwardly from the pivot 70 is a lever arm 72 (Fig. 3) which is oifset outwardly from the edge of slide 55 to provide a working space 73 permitting the lever arm to be finger pressed inwardly to disengage the locking lug or detent 71a from any one of the notches 66-69, as Shown in the broken line position of lever arm 71 in Fig. 1. The olfset lever arm 72 is formed with a lateral extension 72a (Fig. 3) engaged by a small spring 74 seated in a recess in the bracket 56. This spring yieldingly holds the selector lever arm 71 in latching position with respect, to slide 55, being compressed upon pressing the lever'arm 72 inwardly.

It will be apparent that vertical adjustments of the slide 55 will result in positioning the limit switch 52, 53 in corresponding vertically adjusted positions .with respect to the lirnit switch actuating member 35a or, in other words, at variably selected distances from the actuating member.

These adjusted positions of the limit switch are indicated at A ,:B', C an'd D in Fig. 1 which are determinedby latching the slide 55 in the latching notches 66 to 69,

w Theselatter projections also extend radially and, outwardly slightly beyond the projec-v respectively; With, thelimit switch adjustably setat pcsition AI the. honing operationwillbe terminated. after operative entry ofgage ringA into. the workpiece bore. When set, at, position B, the'honing operation will con tinue until gage ring B operativelyenters the bore. With the limit switch set at position Cf the .honing operation will continue until gagering C operatively enters the.

bore. At position D of the limitswitch, which is furthest from the actuating member 35a, the honing opera tion will not terminate until after the workpiece bore is honed to, a size permitting operative entry of gage ring D into the bore. From the foregoing it will be seen that by virtue. of the stepped gage means and the adjustable positions of the limit switch the bore. of the workpiece may be honed to any one of the diameters of'the stepped gages whereupon the limitswitch will be actuated to initiate termination of the honing operation.

In the second. embodiment of the invention illustrated in Figs. 7 to 9 inclusive the limit switch 52, 53 is not mounted. for vertical adjustment. Instead and as distinguished from the first embodiment, the switch actuating means, whichmoves axially in unison with the stepped gage ring means, is adjustable relative to the limit'switch into any one of four selected positions whereby the honing operation will terminate after operative entry of any one or" the gage rings A, B, C and D 'into the workpiece bore. Referring to Figs. 7 to 9 inclusive, the limit switch 52 and switch actuating member 53 are carried by supporting member 54 which is attached to a stationary vertical member 55a secured at its lower end to the bracket 57. In this embodiment the trip block 75, as distinguished from the trip block 34 in thefirst embodiment, is mounted for vertical adjustment on the limit switch control mernf beror arm 32 thereby enabling the limit switch actuating member 35a to be adjustably positioned'at variably selected distances from the limit switch, such adjusted positions being indicated at A B C and D in Fig. 8. The

control member 32 is provided with four notches 7 6,

77, 78 and 79 spaced apart similarly to the notches 66-69 in the first embodiment. The trip block 75 and its arm extension 75a are provided with a horizontal slot 80 which receives a selector locking lever or latch member 81 pivoted at 82 to the arm extension 75a. This locking lever at one side of its pivot may be disposed in any one of the notches 76-79 thereby locking the trip block 75 in adjusted position on the control member 32. The locking lever at the opposite side of its pivot is offset. out

wardly in the slot 80, see Fig. 9, and terminates in an enlargeclfinger piece 81a whichis spaced at 83 from the trip block arm extension 75a thereby enabling the finger spectively at positions A B C and D With the switch.

actuating member adjustably set at position A? the honing operation will be terminated upon operative entry of gage ring A intothe workpiece bore. Likewise when the switch actuating member is adjustably set at position B position C or position D the honing operation willbe I terminated upon operative entry respectively of gage r ng B, C or D into the workpiece bore.

In the third embodiment of the invention illustrated m Fig. 10 the stepped gage ring means is adjustable axially as a unit into any one of four selected positions whereby the honing operation will terminate after operative entry of any one of the gage rings A, B, C and D into the work.

piece bore. As described injconnection with the first.

embodiment the gage'rings A, B,-'C and D are securely clamped in position on tubular gage holder 38 which i This spring provided with internal threads in threaded engagement with the threads 24b on the gage support 24. By virtue of this threaded connection the gage hoder 38 may be adjusted axially into four positions indicated at A B, C and D thereby varying the time of engagement of switch actuating member 35a with limit switch 53. With the gage holder 38 adjusted to position A the switch actuating member 35a will engage and actuate the limit switch upon operative entry of gage ring A into the workpiece bore. When adjusted to position B the limit switch 53 will be actuated upon honing the bore to a size permitting operative entry of gage ring B into the bore. With the gage holder adjusted to position C the limit switch will be actuated upon operative entry of gage ring C into the bore. When the gage holder is adjusted to position D the limit switch will be actuated upon honing the bore .to a size permitting operative entry of gage ring D into the bore. 7

In order to ensure accurate axial adjustment of the gage holder 38 into any one of positions A D the bottoms of the slots 37 in gage support 24 may be provided with 10- cating marks for positioning the upper face of the gage holder. With respect to the third embodiment it will be understood that the limit switch 52, 53 is not mounted for vertical adjustment as in the first embodiment nor is the trip block mounted for adjustment on control member 32 as in the second embodiment.

Although in the several embodiments illustrated four varying diameter gage rings A, B, C and D are provided, it will be understood that the number of gage rings may be increased or decreased. The effective diameters of the series of gage rings may vary in dimensional increments of one half a thousandth of an inch or in larger increments enabling the honing of bores to effective diameters having an over-all variation of two or more thousandths of an inch. The invention thus enables different diameter bores to be honed, or bores to be honed to different diameters, merely by making simple adjustments as herein illustrated, thereby effecting important savings in time previously required in removing and dismantling the tool in order to change gage rings so as to accomplish the results achieved by the present invention.

I claim:

1. In a honing apparatus for honing the bore of a tubular workpiece having reciprocable and rotatable spindle means and honing means mounted adjacent one end thereof, a reciprocable annular plug gage unit encircling said spindle means and operative at the end of the workpiece bore through which the honing means enters to hone said bore, said gage unit comprising a series of juxtaposed gage rings having annularly spaced radially proecting gaging portions increasing in effective diameter in the direction away from the honing means, and means effective to initiate cessation of the honing operation upon predetermined operative entry into the workpiece bore of the gaging portions of any one of said gage rings.

2. In a honing apparatus for honing the bore of a tubular workpiece having reciprocable and rotatable spindle means and honing means mounted adjacent one end thereof, a reciprocable annular plug gage unit encircling said spindle means and operative at the end of the workpiece bore through which the honing means enters to hone said bore, said gage unit comprising a series of juxtaposed gage rings having annularly spaced radially projecting gaging portions increasing in effective diameter in the direction away from the honing means, and means for pre-selecting any one of said gage rings to initiate termination of the honing operation upon operative entry of such pre-selected gage ring into the workpiece bore.

3. In a honing apparatus for honing the bore of a tubular workpiece having reciprocable and rotatable spindle means and honing means mounted adjacent one end thereof, a reciprocable annular plug gage unit encircling said spindle means and operative at the end of the workpiece bore through which the honing means enters to hone said bore, said gage unit comprising successive stepped gage ring means increasing in one direction in effective diameter for selectively controlling the effective diameter to which the workpiece bore is to be honed, switch control means for initiating termination of the honing operation by releasing the honing means from honing engagement with the workpiece bore, actuating means movable in unison with said gage unit for actuating said switch control means, and means adjustable in a direction parallel to the axis of said spindle means for varying actuation of said switch control means by said actuating means to correspond to operative entry of any one of said stepped gage ring means into the workpiece bore.

4. Honing apparatus according to claim 3 wherein said adjustable means comprises means for adjusting the position of said switch control means relative to said actuating means.

5. Honing apparatus according to claim 3 wherein said adjustable means comprises means for adjusting the position of said actuating means relative to said switch control means.

6. Honing apparatus according to claim 3 wherein said adjustable means comprises means for adjusting axially the position of said gage unit relative to said switch control means and actuating means.

7. Honing apparatus according to claim 3 wherein said adjustable means comprises means adapted to be adjusted to vary the relative positions of said switch control means and actuating means.

8. In a honing apparatus for honing the bore of a tubular workpiece having reciprocable and rotatable spindle means and honing means mounted adjacent one end thereof, a reciprocable annular plug gage unit encircling said spindle means and operative at the end of the workpiece bore through which the honing means enters to hone said bore, said gage unit comprising a plurality of stepped gage portions successively varying in effective diameter, and means for initiating cessation of the honing operation upon operative entry into the workpiece bore of any pre-selected diametrical step portion of said gage unit.

9. Honing apparatus according to claim 8 comprising means for mounting said gage unit for limited but substantially free movement transversely of the spindle means an amount equal to ten thousandths of an inch or more.

10. In a honing apparatus for honing the bore of a tubular workpiece having reciprocable and rotatable spindle means and honing means mounted adjacent one end thereof, a reciprocable annular plug gage unit encircling said spindle means and operative at the end of the workpiece bore through which the honing means enters to hone said bore, said gage unit comprising successive stepped gage ring means increasing in effective diameter in the direction away from the honing means for selectively controlling the effective diameter to which the workpiece bore is to be honed, switch control means for initiating termination of the honing operation by releasing the honing means from honing engagement with the workpiece bore, actuating means movable in unison with said gage unit for actuating said switch control means, and means adjustable in a direction parallel to the axis of said'spindle means for varying actuating of said switch control means by said actuating means to correspond to operative entry of any one of said stepped gage ring means into the workpiece bore.

1.1. Honing apparatus according to claim 1 comprising piece bore through which the honing means enters to hone said bore, said gage unit comprising gage ring means having a plurality of gaging portions successively varying in effective diameter, switch control means adapted to be actuated for initiating cessation of the honing operation, actuating means movable in unison with said gage unit for actuating said switch control means, and adjustable means for varying actuation of said switch control means by said actuating means to correspond to operative entry of any one of said portions of said gage ring means into the workpiece bore, said adjustable means comprising means for adjusting the position of said switch control means relative to said actuating means.

13. In a honing apparatus for honing the bore of a tubular workpiece having reciprocable and rotatable spindle means and honing means mounted adjacent one end thereof, a reciprocable annular plug gage unit encircling said spindle means and operative at the end of the workpiece bore through which the honing means enters to hone said bore, said gage unit comprising gage ring means having a plurality of gaging portions successively varying in effective diameter, switch control means adapted to be actuated for initiating cessation of the honing operation, actuating means movable in unison with said gage unit for actuating said switch control means, and adjustable means for varying actuation of said switch control means by said actuating means to correspond to operative entry of any one of said portions of said gage ring means into the workpiece bore, said adjustable means comprising means for adjusting axially the position of said gage unit relative to said switch control means and actuating means.

References Cited in the file of this patent FOREIGN PATENTS 1,094,595 France Dec. 8, 1954 

